(1) Field of the Invention:
The present invention relates to overhead type file sheet projectors which can directly project slides in an enlarged scale in the state that they are held in a file sheet, file sheets and jacket holders for use in such overhead type file sheet projectors.
(2) Related Art Statement:
As shown in FIGS. 14 and 15, in a conventional overhead type file sheet projector, a lower stage 28 is movable to-and-fro by means of guide rails provided on opposite sides of a projector body at an upper portion thereof, and an upper stage 29 is fitted to guides 30 provided at front and rear upper end portions of the lower stage 28 in a direction orthogonal to the guide rails. The upper stage is slidably right and left supported by guide rollers 31. A file sheet 15 to which a number of color slides are preliminarily mounted is fitted to the upper stage 29, and the color slides are located and projected at a given position by moving the stage to-and-fro and right and left.
However, in such a conventional projector, when a hard file sheet having a relatively great thickness is to be mounted on the upper stage, members for locating and holding the file sheet in place must be provided at four sides of the upper stage so that the file sheet may not slip. Therefore, since the file locating holders hinder fitting and detachment of the file sheet, smooth fitting and detachment could not be made. In particular, since the vertical length varies among file sheets, the file sheet having a shorter length needs to be pressed and fixed to one side by using a spring.
Further, since the conventional projector is provided with two stages, its construction is complicated and operation of both the stages is troublesome.